There is considerable interest in the development of renewable energy sources to replace petroleum-based fuels. The collection of solar energy is an abundant renewable energy source. Currently only a very small percentage of the energy received from the sun is used by man. A number of systems are available that convert solar energy into electricity. These systems range from small generators to large electricity producing arrays.
Typical photovoltaic cells used in current solar systems are inefficient. Even with concentrated light and a cooled photovoltaic cell, efficiencies are hoped to break 50% in the future. Practically speaking the efficiency of such systems are much lower. Moreover, the cost per kilowatt hour is much higher than the cost of a kilowatt hour from conventional energy production systems.